Do social networks have to be viral?

Don’t get me wrong, I’m a big fan of Facebook. But the fact is that in most scenarios, I cant read certain info without adding an application, and I can’t add an application without inviting friends, and I can’t accept an invitation to add an application without adding icons and banners to my already cluttered profile.
In my opinion, all this forced noise takes allot away from the subtlety of normal socializing. And i find in quite harassing that I can’t get results for a quiz i spent a few minutes taking, without being forced to harass 5 of my friends.
Don’t get me wrong, I enjoy the social aspects of social networks, and I invite friends to apps I find cool, and send them messages and wall posts. But being forced to send them requests every time I do something is a bit to much. If I like something, I love sharing it. But prompting me to invite all my friends and install 72 icons before I even try out the app is slightly outrageous.